As integrated circuits (ICs) increase in complexity over time and include more active devices, the number of signals needed to connect an IC to other components in an electronic system increases. More complex ICs often consume increasing amounts of power, which in turn also requires a larger number of electrical connection points on the IC to adequately supply current.
Ball grid array (BGA) electronic packages are often used to connect IC die to a printed circuit (PC) board. BGA packages are used to interconnect both signals and power between the PC board and the IC die, through an arrangement of solder ball connections at the interface between the BGA package and the PC board. The need for increasing numbers of connections to complex ICs has caused an increase in the interface areas of both the BGA package and the PC board, in order to provide more BGA ball connection sites.
Electrical signal connections to ICs through electronic packages are typically not redundant, so each signal connection from the IC to a PC board (or other connecting structure) is essential for the IC's intended operation. A faulty signal connection, in the form of an open, a short, or an intermittent can cause an IC to catastrophically malfunction. The reliability of IC interconnections to PC boards and other structures is therefore critically important to ensure the proper function of the IC in an electronic system.